112:2. One should not recite insertions (lit. P’yutim) or poetic liturgy (lit. K’Rovetz – some say that the word K’Rovetz is an acronym Kol Rinah V’Yeshua B’Ohalei T’Zeikim [a voice of praise and salvation in the tents of the righteous], one such insertion) [in the first or last three blessings]. {Rama: (3) Some permit [insertions] since they are for communal requests, and so is our universal custom, to (4) recite them.}